Reception of broadcast programming, such as digital video and audio, by way of satellite communication has become both convenient and commonplace. Typically, a satellite communication receiver, an associated satellite dish, and a paid subscription to a satellite broadcast service are all that are required for a customer to receive many different types of programming, including news, sports, and entertainment broadcasts. Generally, the programming may include a basic package of programming to which the customer may subscribe for a monthly fee. In addition, the customer may receive premium programming and various one-time events for an additional amount, thus providing the subscriber flexibility in the programming received and the amount paid therefor. However, though many consumers consider subscription rates for satellite programming to be at least reasonable when compared to alternative forms of communication, others will go to great lengths to obtain satellite broadcast service illegally without subscribing to the service.
To prevent piracy of satellite broadcast service, a combination of electronic hardware, software and data encryption technology is often employed to allow only valid subscribers to receive the satellite broadcast service. Most programming transmitted from the satellite is typically encrypted, or “scrambled,” requiring the receiver to decrypt the programming through use of a security “key” or other information in conjunction with a decryption algorithm. In a typical example, each satellite receiver contains a reader unit into which is installed a “smart card,” which provides security for the broadcast communications. More specifically, the smart card normally contains information identifying the particular programming a user of the satellite receiver is licensed to receive, as well as the information necessary to decrypt the programming.
After a customer subscribes to a particular set of programming available through the satellite communication service and configures the satellite receiver for operation, a satellite transmits one or more messages intended for that specific receiver to program the smart card with the necessary information to allow the receiver to receive and display the appropriate programming. These messages may also include the information required to decrypt the programming. When the consumer alters their subscription, these changes are also made in the smart card via satellite.
While various security measures are implemented to prevent unauthorized access to the security keys within the smart card, determined individuals, given enough time and resources, ultimately may be able to defeat those measures, allowing them free unauthorized access to the satellite broadcast services. Such a possibility is a primary reason why the smart card is used as a security device, since changes in those measures to eliminate unauthorized access may be implemented by issuing each authorized subscriber a new smart card incorporating a new security implementation. As a result, replacement of the entire receiver to alter the security measures is avoided.
Nonetheless, given the intelligence and persistence of those determined to defeat the security measures and obtain satellite broadcast service illegally, additional enhancements to the security of such services that makes unauthorized access to programming more difficult are often desirable.